Android String.format() Returns Question Mark (??) [FIXED] -
i have app downloads files internet. source file name dynamically generated depending on user selection. use following method create source file name. note fileid integer (1-99). final string filename = "file_" + string.format("%02d", fileid) + "_download.jpg"; the issue have seen users unable download files (and of course leave 1 start ratings :( ). when check server log see download requests came file names file_??_download.jpg . looks string.format() has returned ?? instead of 2 digit number. i searched everywhere , not find solution this. can tell me what's wrong code? not re-produce error on of devices. thanks! you have instead: final string filename = "file_" + string.format("%d", fileid) + "_download.jpg"; or final string filename = "file_" + fileid + "_download.jpg"; if want 2 last digits, it: int formattedfileid = fileid % 100; final string filename = "fil...